修復 too many connection 問題

lib/smart-ip-detector.ts

@@ -0,0 +1,208 @@
+// =====================================================
+// 智能 IP 偵測器
+// =====================================================
+
+import { NextRequest } from 'next/server';
+
+export interface IPDetectionResult {
+  detectedIP: string;
+  confidence: 'high' | 'medium' | 'low';
+  source: string;
+  allCandidates: string[];
+  isPublicIP: boolean;
+}
+
+export class SmartIPDetector {
+  private static instance: SmartIPDetector;
+  
+  public static getInstance(): SmartIPDetector {
+    if (!SmartIPDetector.instance) {
+      SmartIPDetector.instance = new SmartIPDetector();
+    }
+    return SmartIPDetector.instance;
+  }
+
+  // 檢查是否為公網 IP
+  private isPublicIP(ip: string): boolean {
+    if (!ip || ip === 'unknown') return false;
+    
+    // 本地地址
+    if (ip === '127.0.0.1' || ip === '::1' || ip === 'localhost') return false;
+    
+    // 私有地址範圍
+    if (ip.startsWith('192.168.') || 
+        ip.startsWith('10.') || 
+        ip.startsWith('172.') ||
+        ip.startsWith('169.254.')) return false;
+    
+    // IPv6 本地地址
+    if (ip.startsWith('fe80:') || 
+        ip.startsWith('::1') || 
+        ip.startsWith('::ffff:127.0.0.1')) return false;
+    
+    return true;
+  }
+
+  // 從 x-forwarded-for 解析 IP
+  private parseForwardedFor(forwarded: string): string[] {
+    if (!forwarded) return [];
+    
+    return forwarded
+      .split(',')
+      .map(ip => ip.trim())
+      .filter(ip => ip && ip !== 'unknown');
+  }
+
+  // 智能偵測客戶端 IP
+  public detectClientIP(request: NextRequest): IPDetectionResult {
+    const candidates: string[] = [];
+    const sources: { [key: string]: string } = {};
+
+    // 1. 收集所有可能的 IP 來源
+    const headers = {
+      'x-forwarded-for': request.headers.get('x-forwarded-for'),
+      'x-real-ip': request.headers.get('x-real-ip'),
+      'cf-connecting-ip': request.headers.get('cf-connecting-ip'),
+      'x-client-ip': request.headers.get('x-client-ip'),
+      'x-forwarded': request.headers.get('x-forwarded'),
+      'x-cluster-client-ip': request.headers.get('x-cluster-client-ip'),
+      'x-original-forwarded-for': request.headers.get('x-original-forwarded-for'),
+      'x-remote-addr': request.headers.get('x-remote-addr'),
+      'remote-addr': request.headers.get('remote-addr'),
+      'client-ip': request.headers.get('client-ip'),
+    };
+
+    // 2. 從各個標頭提取 IP
+    Object.entries(headers).forEach(([header, value]) => {
+      if (value) {
+        if (header === 'x-forwarded-for') {
+          const ips = this.parseForwardedFor(value);
+          ips.forEach(ip => {
+            candidates.push(ip);
+            sources[ip] = header;
+          });
+        } else {
+          candidates.push(value);
+          sources[value] = header;
+        }
+      }
+    });
+
+    // 3. 添加 NextRequest 的 IP (如果可用)
+    const nextIP = (request as any).ip;
+    if (nextIP) {
+      candidates.push(nextIP);
+      sources[nextIP] = 'next-request';
+    }
+
+    // 4. 去重並過濾
+    const uniqueCandidates = [...new Set(candidates)].filter(ip => 
+      ip && ip !== 'unknown' && ip !== '::1' && ip !== '127.0.0.1'
+    );
+
+    console.log('🔍 IP 偵測候選:', {
+      candidates: uniqueCandidates,
+      sources: sources,
+      allHeaders: Object.fromEntries(request.headers.entries())
+    });
+
+    // 5. 智能選擇最佳 IP
+    let selectedIP = 'unknown';
+    let confidence: 'high' | 'medium' | 'low' = 'low';
+    let source = 'unknown';
+
+    // 優先級 1: Cloudflare IP (最高可信度)
+    const cfIP = uniqueCandidates.find(ip => sources[ip] === 'cf-connecting-ip');
+    if (cfIP && this.isPublicIP(cfIP)) {
+      selectedIP = cfIP;
+      confidence = 'high';
+      source = 'cf-connecting-ip';
+    }
+
+    // 優先級 2: 其他代理標頭中的公網 IP
+    if (selectedIP === 'unknown') {
+      const proxyHeaders = ['x-real-ip', 'x-client-ip', 'x-cluster-client-ip'];
+      for (const header of proxyHeaders) {
+        const ip = uniqueCandidates.find(candidate => sources[candidate] === header);
+        if (ip && this.isPublicIP(ip)) {
+          selectedIP = ip;
+          confidence = 'high';
+          source = header;
+          break;
+        }
+      }
+    }
+
+    // 優先級 3: x-forwarded-for 中的第一個公網 IP
+    if (selectedIP === 'unknown') {
+      const forwardedIPs = uniqueCandidates.filter(ip => sources[ip] === 'x-forwarded-for');
+      const publicForwardedIP = forwardedIPs.find(ip => this.isPublicIP(ip));
+      if (publicForwardedIP) {
+        selectedIP = publicForwardedIP;
+        confidence = 'medium';
+        source = 'x-forwarded-for';
+      }
+    }
+
+    // 優先級 4: 任何公網 IP
+    if (selectedIP === 'unknown') {
+      const publicIP = uniqueCandidates.find(ip => this.isPublicIP(ip));
+      if (publicIP) {
+        selectedIP = publicIP;
+        confidence = 'medium';
+        source = sources[publicIP] || 'unknown';
+      }
+    }
+
+    // 優先級 5: 任何非本地 IP
+    if (selectedIP === 'unknown') {
+      const nonLocalIP = uniqueCandidates.find(ip => 
+        ip !== '::1' && ip !== '127.0.0.1' && !ip.startsWith('192.168.') && 
+        !ip.startsWith('10.') && !ip.startsWith('172.')
+      );
+      if (nonLocalIP) {
+        selectedIP = nonLocalIP;
+        confidence = 'low';
+        source = sources[nonLocalIP] || 'unknown';
+      }
+    }
+
+    // 優先級 6: 第一個候選 IP
+    if (selectedIP === 'unknown' && uniqueCandidates.length > 0) {
+      selectedIP = uniqueCandidates[0];
+      confidence = 'low';
+      source = sources[selectedIP] || 'unknown';
+    }
+
+    const result: IPDetectionResult = {
+      detectedIP: selectedIP,
+      confidence,
+      source,
+      allCandidates: uniqueCandidates,
+      isPublicIP: this.isPublicIP(selectedIP)
+    };
+
+    console.log('🎯 IP 偵測結果:', result);
+
+    return result;
+  }
+
+  // 驗證 IP 格式
+  public isValidIP(ip: string): boolean {
+    if (!ip || ip === 'unknown') return false;
+    
+    // IPv4 格式檢查
+    const ipv4Regex = /^(\d{1,3}\.){3}\d{1,3}$/;
+    if (ipv4Regex.test(ip)) {
+      const parts = ip.split('.').map(Number);
+      return parts.every(part => part >= 0 && part <= 255);
+    }
+    
+    // IPv6 格式檢查（簡化）
+    const ipv6Regex = /^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$/;
+    return ipv6Regex.test(ip);
+  }
+}
+
+// 導出單例實例
+export const smartIPDetector = SmartIPDetector.getInstance();